[Aztlan] Jaguars in Formative Valley of Mexico

[Jaime Pretell]

I would disagree with that interpretation that leopards per se are older 
than jaguars. Just their lineage.
----- Original Message ----- 
From: "Bruce Rogers" <bwrogers at dslextreme.com>
> The paleontological record has shown that jaguars evolved from
> leopards, a genus that itself apparently evolved in India some 5
> million years ago, or at least that's what the current fossil record
> tells us.

The jaguar and the leopard do indeed descend from the same branch, but that 
ancestor was not a leopard, just the common ancestor of both. In fact the 
earliest evidences of leopards had more jaguar like traits than leopardine. 
It is only because this common ancestor was in Asia that they called them 
leopards. By taxonomy they would have been refered to as Jaguars.
http://golab.unl.edu/teaching/SBseminar/leopardMOLECOL.pdf

 If anything, the basal group as far as most distant in genetic divergence 
in modern populations it is the clouded leopard.

Genetic relationships between Leopard and jaguar are shown on pages 341-352 
and show the Jaguar to split from the Leopard and the lion at different 
points depending on the marker. The final chart shows the divergence of the 
leopard line and the lion/jaguar line is first and then jaguars and lions 
diverge from each other. But again, those ancestors did not look like 
leopards, but more like jaguars in shape.
http://home.ncifcrf.gov/ccr/lgd/staffinfo/staff/pdf/Johnson_genetic%20assess_suppdata_vol311.pdf

As to Jaguars in the lake basin in the valley of Mexico I have yet to find 
any study that indicates such fossil or skeletal remains.  I would love to 
read it.  It sounds like an interesting read. You wouldn't have a link would 
you?